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对一种新型中高碳贝氏体钢的组织,转为动力学和耐磨性进行了研究,中高碳贝氏体钢空冷后的组织为贝氏体,马氏体,碳化物和残留奥氏体,组织细小均匀,大截面实物硬度测定和组织观察表明,截面上具有高硬度,并组织分布均匀,中高碳贝氏体钢具有高的耐磨性。 相似文献
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采用前驱体碳化复合技术制备了Ti-Fe-C和Ti-Ni-C两种体系的反应热喷涂复合粉末,通过氧乙炔火焰喷涂原位合成并沉积了TiC增强Fe基和Ni基复合涂层.利用XRD、SEM和EDS研究了复合粉末、涂层的相组成和组织结构,考察了TiC/Fe、TiC/Ni复合涂层的硬度和耐磨性.结果表明: 复合粉末在喷涂过程中反应充分,可分别生成以Fe和Ni为粘结相的TiC增强涂层;两种涂层都是由TiC颗粒均匀分布的复合强化片层和TiC聚集片层叠加而成,TiC/Fe复合涂层的片层较薄,而TiC/Ni涂层中TiC的聚集片层较少;TiC/Fe涂层的硬度高于TiC/Ni涂层,两者的耐磨性能分别约为Ni60涂层的11倍和6倍. 相似文献
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本试验研究了不同淬火和回火工艺热处理对Cr12MoV钢组织、硬度和磨损性能的影响。实验结果表明:当在1050~1100℃范围内淬火、520℃回火时,得隐针马氏体+少量残余奥氏体组织,材料硬度与耐磨性均较好;当在1100℃淬火,各温度二次回火硬度均较一次回火高,当在550℃回火时,试验钢实现二次硬化,且残余奥氏体大量转变,硬度和耐磨性达最大值,材料性能最优。 相似文献
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通过凝固实验并结合Thermo-Calc软件研究了高钛钢(Ti 质量分数为0.6%)在凝固过程中 TiC 的析出方式及形态.结果表明:由于选分结晶的作用,TiC在凝固最后阶段沿着原始奥氏体晶界析出,并形成离异共晶组织,以片状或杆状形式存在,析出相厚度约为1~3μm.Mo 溶入 TiC 后形成(Ti,Mo)C,相分析数据表明,Ti/Mo 质量比为3.4.采用热力学软件及TiC溶解度积分别得出TiC开始析出温度分别为1453及1487℃,析出温度略高于固相线温度,析出质量分数可以达到0.35%. 相似文献
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采用激光熔覆技术在40 Cr Ni Mo基材上制备了TiC增强双相不锈钢复合熔覆层,熔覆层物相主要由奥氏体、马氏体、M7C3型碳化物和TiC组成。其中M7C3型碳化物主要包括Fe7C3、Cr7C3或者(Fe、Cr)7C3三种,TiC按尺寸可分为熔解后析出的微米级TiC以及粗大的未熔TiC颗粒。析出的TiC颗粒为方块状,随着TiC添加量增加,呈花瓣状长大。未熔TiC颗粒与基材形成了扩散界面,具有很好的界面结合性。当加入30 wt.%TiC时,熔覆层具有最好的耐磨性,硬度可达55.26 HRC,磨损体积为2.54×10-2 mm3,耐磨性是基材的3.37倍。 相似文献
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Microstructure and Wear Resistance in Medium and High C Steels Treated by Quenching and Partitioning
Eider Del Molino Maribel Arribas Iñaki Pérez Félix Valdavida Javier Jesús González 《国际钢铁研究》2023,94(8):2300056
The quenching and partitioning (Q&P) steels have shown to be promising candidates to be applied in fields where wear resistance is required. In this study, a medium and a high C steel are heat treated by Q&P and the resulting microstructure, hardness, and wear resistance are characterized. The mechanical stability of the austenite phase under wear test conditions is investigated. It is found that the stability of austenite is very high in the high C steel and decreases in the medium C steel. Additionally, the hardness and wear behavior of the Q&P-treated steels are compared with the results obtained for quenching and tempering (Q&T) treated samples, showing that, although the hardness of Q&P steels is quite lower, the obtained wear rates are similar. It means that in the studied Q&P steels, although the austenite transformation into martensite does not occur considerably, the presence of austenite might play a key role in the wear resistance. 相似文献
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This study is concerned with the correlation of microstructure and abrasive and sliding wear resistance of (TiC,SiC)/Ti-6Al-4V
surface composites fabricated by high-energy electron-beam irradiation. The mixtures of TiC, SiC, Ti + SiC, or TiC+SiC powders
and CaF2 flux were deposited on a Ti-6Al-4V substrate, and then an electron beam was irradiated on these mixtures. The surface composite
layers of 1.2 to 2.1 mm in thickness were homogeneously formed without defects and contained a large amount (30 to 66 vol
pct) of hard precipitates such as TiC and Ti5Si3 in the martensitic matrix. This microstructural modification, including the formation of hard precipitates in the surface
composite layer, improved the hardness and abrasive wear resistance. Particularly in the surface composite fabricated with
TiC + SiC powders, the abrasive wear resistance was greatly enhanced to a level 25 times higher than that of the Ti alloy
substrate because of the precipitation of 66 vol pct of TiC and Ti5Si3 in the hardened martensitic matrix. During the sliding wear process, hard and coarse TiC and Ti5Si3 precipitates fell off from the matrix, and their wear debris worked as abrasive particles, thereby reducing the sliding wear
resistance. On the other hand, needle-shaped Ti5Si3 particles, which did not play a significant role in enhancing abrasive wear resistance, lowered the friction coefficient
and, accordingly, decelerated the sliding wear, because they played more of the role of solid lubricants than as abrasive
particles after they fell off from the matrix. These findings indicated that high-energy electron-beam irradiation was useful
for the development of Ti-based surface composites with improved abrasive and sliding wear resistance, although the abrasive
and sliding-wear data should be interpreted by different wear mechanisms. 相似文献
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Chang Sup Lee Jun Cheol Oh Sunghak Lee 《Metallurgical and Materials Transactions A》2003,34(7):1461-1471
The objective of this study is to investigate microstructure, hardness, and wear properties of three kinds of (TiC,TiB)/Ti-6Al-4V
surface-alloyed materials fabricated by high-energy electron-beam irradiation. The mixtures of Ti+C, TiC+TiB2, and Ti+B4C powders and CaF2 flux were deposited on a Ti-6A1-4V substrate, and then high-energy electron beam was irradiated on these mixtures. The surface-alloyed
layers of 0.9 to 1.6 mm in thickness were homogeneously formed, and contained a large amount (30 to 44 vol. pct) of hard precipitates
such as TiC and TiB in the martensitic matrix. This microstructural modification improved the hardness and wear resistance
of the surface-alloyed layer 2 times and 6 to 9 times, respectively, greater than that of the substrate. Particularly, the
surface-alloyed material fabricated with Ti+B4C powders had a larger volume fraction of TiB and TiC homogeneously distributed in the martensitic matrix, and thus showed
the best hardness and wear resistance. These findings suggested that the surface-alloying using high-energy electron-beam
irradiation was economical and useful for the development of titanium-base surface-alloyed materials with improved hardness
and wear properties. 相似文献
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采用球磨与热等静压相结合的方法制备TiC_p/30Cr Ni4Mo钢基复合材料,研究材料的显微组织、密度、硬度、常温和高温拉伸性能以及摩擦磨损性能。结果表明,TiC_p/30Cr Ni4Mo钢基复合材料的组织均匀细小,基体组织主要为细片状珠光体、铁素体和少量残余奥氏体,Ti C颗粒弥散分布在基体上,与基体结合牢固;复合材料的相对密度高达99.7%,硬度为49 HRC,抗拉强度高达1 266 MPa,伸长率为4.0%;复合材料具有较好的高温力学性能,400℃时复合材料抗拉强度仍高达1 135 MPa;在200 N载荷条件下,复合材料的耐磨损性能较原30Cr Ni4Mo材料提高约4倍,磨损形式主要表现为轻微的磨粒磨损;复合材料经950℃水淬和520℃回火后,抗拉强度高达1 325 MPa,伸长率为4.6%。 相似文献
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以电解铜粉和TiC粉为原料, 采用粉末冶金法制备了增强体质量分数为5%、10%、15%、20%的TiC颗粒增强铜基复合材料。通过对显微组织的观察和对相对密度、硬度、电导率、磨损率、摩擦系数的测试, 研究了增强相质量分数、烧结温度对复合材料组织性能的影响。研究结果表明, TiC颗粒除少量团聚外均匀分布在基体上, 并与基体结合良好; 随烧结温度升高, 铜基复合材料的密度和硬度均有所增加; 随增强相质量分数的增加, 硬度增加, 相对密度和电导率均有所下降; 磨损率则表现为先降低后有所增加的趋势, 磨损率在TiC质量分数为15%时最低; 铜基复合材料的摩擦系数明显低于纯铜, 其磨损机制主要以磨粒磨损为主。 相似文献
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Comparison of the microstructures and abrasive wear properties of stellite hardfacing alloys deposited by arc welding and laser cladding 总被引:1,自引:0,他引:1
The microstructure of cobalt-based hardfacing alloys deposited by manual metal arc (MMA) welding, tungsten inert gas (TIG)
welding, and laser cladding has been investigated as part of a study attempting to establish the relationship between microstructure
and abrasive wear properties. For typical deposition conditions, the differences in freezing rates associated with the three
processes are found to give rise to large differences in microstructure. The MMA process is found to lead to the largest degree
of dilution of the hardfacing deposit; the TIG and laser deposits exhibited much lower levels of mixing with the base plate.
For the deposition conditions used in this study and for the alloys examined, the scale of the microstructure decreases in
the order MMA, TIG, and laser cladding, leading to an increase in the deposit hardness in the same order. It is found that
with alumina as an abrasive, the wear rate persistently is higher with the MMA deposits (which have the coarsest microstructure
with the lowest starting hardness), the weight loss being approximately linear with time. The laser and TIG deposits, which
have more refined microstructures and slightly higher carbon concentrations, both are found to exhibit significantly lower
wear rates. Initially, the TIG samples are the most resistant to abrasion, even though their microstructure compares with
that of the laser samples; this is a consequence of their higher ductility associated with a lower rate of strain hardening.
The laser samples, which contain a lower matrix iron concentration, strain harden more rapidly; consequently, they exhibit
an initial decrease in wear rate. With the much harder silicon carbide abrasive, all samples show similar wear rates which
do not decrease with time. The wear data are found to correlate with scanning and transmission electron microscopy observations,
and it is possible to rationalize the interaction among microstructure, abrasive, and alloy deposition processes. 相似文献
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In the present study, Ni-based Colmonoy 5 was deposited on Type 316L (N) stainless steel. The deposit was aged at 580 and 650°C for 5,000 h to study the influence of aging on sliding wear resistance. The aged deposits show more wear loss due to reduced hardness. However, the reduced hardness after aging was not reflected on wear test at 550°C irrespective of sliding distance. This is due to stability of microstructure as well as the generation of oxide layer during high temperature tests. Subsequently, an empirical relation was developed based on outcome experimental data using full factorial design of experiments in terms of hardness (H), test temperature (T) and sliding distance (D). Based on the empirical relation, it was found that the test temperatures (T) play a predominant role on wear loss than hardness (H) and sliding distance (D). Further, the developed relationships were validated using analysis of variance (ANOVA). 相似文献